Half and half mixture of peat moss and sand is good or some gardeners have had luck using well-rotted compost, which has been sieved carefully to remove clods and twigs.

If the soil is a very heavy clay it might be practical to try to lighten it with the addition of well-rotted compost or, if it is locally available, coarse builder's sand.

There is also no risk of nitrogen robbery when comfrey is dug into the soil as the C:N ratio of the leaves is lower than that of well-rotted compost.

Use a balanced fertilizer or well-rotted compost to maintain nutrition and a bulb booster mixed into the bottom of the hole when planting bulbs, because it is high in phosphorus, which does not move much in the soil.

The foliage can be cut in autumn, and a mulch, such as leaf mould or well-rotted compost applied to the plot.

It should not be a heavy clay, but preferably a slightly damp, crumbly garden soil with a little well-rotted compost added to it.

Dig over the ground lightly, and incorporate some well-rotted compost to feed the soil if necessary.

Adding well-rotted compost every spring and lots of water during the growing season will result in better flowering in the coming seasons.

In addition, well-rotted compost should be put in the hole to provide the best habitat for plant growth.

If a large patch of ground cover is to be set out, many gardeners like to cover the ground first with a good blanket of well-rotted compost to keep any weed growth down and provide anchorage for the new plants.